Is ug like a chunk of swiss cheese? Evidence for a third-factor principle

The word order of the serial verb constructions provides evidence for a "third-factor principle" at work. While what we know about UG linearizes syntactic constituents on the basis of hierarchical structure, serial verbs are linearized in accordance with iconicity. with the same semantic relation mapping to a constant word order but to varying structural relations. The utilization of iconic linearization under strict conditions may be viewed as a case of general cognitive mechanisms at work when UG has a functional gap for sentence-generation.